scholarly journals TRIM37 prevents formation of centriolar protein assemblies by regulating Centrobin

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Fernando R Balestra ◽  
Andrés Domínguez-Calvo ◽  
Benita Wolf ◽  
Coralie Busso ◽  
Alizée Buff ◽  
...  
Keyword(s):  
Ubiquitin Ligase ◽  
De Novo ◽  
Tumor Formation ◽  
Genome Integrity ◽  
Protein Assemblies ◽  
Culture Cells ◽  
Mulibrey Nanism ◽  
Tissue Culture Cells ◽  
Assembly Pathway ◽  
The Stability

TRIM37 is an E3 ubiquitin ligase mutated in Mulibrey nanism, a disease with impaired organ growth and increased tumor formation. TRIM37 depletion from tissue culture cells results in supernumerary foci bearing the centriolar protein Centrin. Here, we characterize these centriolar protein assemblies (Cenpas) to uncover the mechanism of action of TRIM37. We find that an atypical de novo assembly pathway can generate Cenpas that act as microtubule-organizing centers (MTOCs), including in Mulibrey patient cells. Correlative light electron microscopy reveals that Cenpas are centriole-related or electron-dense structures with stripes. TRIM37 regulates the stability and solubility of Centrobin, which accumulates in elongated entities resembling the striped electron dense structures upon TRIM37 depletion. Furthermore, Cenpas formation upon TRIM37 depletion requires PLK4, as well as two parallel pathways relying respectively on Centrobin and PLK1. Overall, our work uncovers how TRIM37 prevents Cenpas formation, which would otherwise threaten genome integrity.

scholarly journals TRIM37 prevents formation of centriolar protein assemblies by regulating Centrobin stability

2020 ◽  
Author(s):  
Fernando R. Balestra ◽  
Benita Wolf ◽  
Andrés Domínguez-Calvo ◽  
Alizée Buff ◽  
Tessa Averink ◽  
...  
Keyword(s):  
Ubiquitin Ligase ◽  
De Novo ◽  
Genome Integrity ◽  
Major Constituent ◽  
Protein Assemblies ◽  
Culture Cells ◽  
Mulibrey Nanism ◽  
Tissue Culture Cells ◽  
Assembly Pathway ◽  
The Stability

ABSTRACTTRIM37 is an E3 ubiquitin ligase mutated in Mulibrey nanism, a disease characterized by impaired growth and increased tumorigenesis, whose cellular etiology is poorly understood. TRIM37 depletion from tissue culture cells results in supernumerary foci bearing the centriolar protein Centrin. Here, we characterized these centriolar protein assemblies (Cenpas) to uncover the mechanism of action of TRIM37. We established that an atypical de novo assembly pathway is notably involved in forming Cenpas, which can nevertheless trigger further centriole assembly and act as MTOCs. We found also that Cenpas are present and act similarly in Mulibrey patient cells. Through correlative light electron microscopy, we uncovered that Cenpas correspond to centriole related structures and elongated electron-dense structures with stripes. Importantly, we established that TRIM37 regulates the stability and solubility of the centriolar protein Centrobin. Our findings suggest that elongated Centrobin assemblies are a major constituent of the striped electron dense structures. Furthermore, we established that Cenpas formation upon TRIM37 depletion requires PLK4 activity, as well as two parallel pathways relying respectively on Centrobin and PLK1. Overall, our work uncovers how TRIM37 prevents the formation of Cenpas that would otherwise threaten genome integrity, including possibly in Mulibrey patients.

scholarly journals Centromere transcription allows CENP-A to transit from chromatin association to stable incorporation

2018 ◽  
Vol 217 (6) ◽  
pp. 1957-1972 ◽  
Author(s):  
Georg O.M. Bobkov ◽  
Nick Gilbert ◽  
Patrick Heun
Keyword(s):  
Rna Polymerase Ii ◽  
Chromatin Remodeling ◽  
Chromosome Segregation ◽  
De Novo ◽  
Histone H3 ◽  
Culture Cells ◽  
Tissue Culture Cells ◽  
Histone H3 Variant ◽  
Loading System ◽  
Stable Incorporation

Centromeres are essential for chromosome segregation and are specified epigenetically by the presence of the histone H3 variant CENP-A. In flies and humans, replenishment of the centromeric mark is uncoupled from DNA replication and requires the removal of H3 “placeholder” nucleosomes. Although transcription at centromeres has been previously linked to the loading of new CENP-A, the underlying molecular mechanism remains poorly understood. Here, we used Drosophila melanogaster tissue culture cells to show that centromeric presence of actively transcribing RNA polymerase II temporally coincides with de novo deposition of dCENP-A. Using a newly developed dCENP-A loading system that is independent of acute transcription, we found that short inhibition of transcription impaired dCENP-A incorporation into chromatin. Interestingly, initial targeting of dCENP-A to centromeres was unaffected, revealing two stability states of newly loaded dCENP-A: a salt-sensitive association with the centromere and a salt-resistant chromatin-incorporated form. This suggests that transcription-mediated chromatin remodeling is required for the transition of dCENP-A to fully incorporated nucleosomes at the centromere.

Cytoplasmic Tubules in Cells Infected with Laryngotracheitis Virus

1969 ◽  
Vol 27 ◽  
pp. 376-377
Author(s):  
A. M. Watrach
Keyword(s):  
Tissue Culture ◽  
Small Proportion ◽  
Chicken Embryo ◽  
Culture Cells ◽  
Tissue Culture Cells ◽  
Morphologic Characteristics ◽  
Infectious Laryngotracheitis ◽  
Laryngotracheitis Virus ◽  
In Cells

During a study of the development of infectious laryngotracheitis (LT) virus in tissue culture cells, unusual tubular formations were found in the cytoplasm of a small proportion of the affected cells. It is the purpose of this report to describe the morphologic characteristics of the tubules and to discuss their possible association with the development of virus.The source and maintenance of the strain of LT virus have been described. Prior to this study, the virus was passed several times in chicken embryo kidney (CEK) tissue culture cells.

Sulfhydryl bond formation is a prerequisite for proper cycling of centrosomes and chromosomes in mammalian tissue culture cells

1993 ◽  
Vol 51 ◽  
pp. 342-343
Author(s):  
Heide Schatten ◽  
Neidhard Paweletz ◽  
Ron Balczon
Keyword(s):  
Tissue Culture ◽  
Cell Cycle Progression ◽  
Group Formation ◽  
Sulfhydryl Group ◽  
Mammalian Tissue ◽  
Mitotic Chromosomes ◽  
Microtubule Network ◽  
Culture Cells ◽  
Tissue Culture Cells ◽  
Transmission Electron

To study the role of sulfhydryl group formation during cell cycle progression, mammalian tissue culture cells (PTK2) were exposed to 100¼M 2-mercaptoethanol for 2 to 6 h during their exponential phase of growth. The effects of 2-mercaptoethanol on centrosomes, chromosomes, microtubules, membranes and intermediate filaments were analyzed by transmission electron microscopy (TEM) and by immunofluorescence microscopy (IFM) methods using a human autoimmune antibody directed against centrosomes (SPJ), and a mouse monoclonal antibody directed against tubulin (E7). Chromosomes were affected most by this treatment: premature chromosome condensation was detected in interphase nuclei, and the structure in mitotic chromosomes was altered compared to control cells. This would support previous findings in dividing sea urchin cells in which chromosomes are arrested at metaphase while the centrosome splitting cycle continues. It might also support findings that certairt-sulfhydryl-blocking agents block cyclin destruction. The organization of the microtubule network was scattered probably due to a looser organization of centrosomal material at the interphase centers and at the mitotic poles.

UDP-D-glucose 4-epimerase activity of the tissue culture of white poplars (Populus alba L. var. pyramidalis)

1982 ◽  
Vol 47 (5) ◽  
pp. 1530-1536 ◽  
Author(s):  
Ladislav Bilisics ◽  
Štefan Karácsonyi ◽  
Marta Kubačková
Keyword(s):  
Tissue Culture ◽  
Cell Walls ◽  
Enzyme Preparation ◽  
Uridine Diphosphate ◽  
Populus Alba ◽  
Activity Change ◽  
White Poplar ◽  
Culture Cells ◽  
Tissue Culture Cells ◽  
Galactose Content

The presence of UDP-D-glucose 4-epimerase (EC 5.1.3.2) in the culture tissue of white poplar was evidenced. As found, the partially purified enzyme preparation contained UDP-D-glucose glucosyltransferase, UDP-D-galactose galactosyltransferase and non-specific enzymes able to cleave the uridine-diphosphate saccharides into the appropriate hexose monophosphates. The activity change of UDP-D-glucose 4-epimerase in tissue culture cells during the growth was in accord with changes in D-galactose content in cell walls and indicated the possibility to regulate the formation of polysaccharides containing D-galactose at the level of production of UDP-D-galactose in cells.

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